The Monarch

Monarchs are classic migrators that arrive in North America roughly from March to July. Their fascinating life history has been closely catalogued by many resources. The progeny of these butterflies generally emerge in late summer to early fall and then migrate either to Mexico or to Coastal California to spend the winter.

Click
here for a video presentation on how to find monarch eggs and caterpillars
in the right habitat in Northern Utah and the Intermountain West.

This is a valley floor wet meadow where you can usually find Monarchs between July through September. Usually these areas are undeveloped agricultural areas and have enough moisture to support Russian Olive Trees. More.

This is showy milkweed, one of the larval host plants of the Monarch. The scientific name for this particular variety is Asclepias speciosa. They call it milkweed because it bleeds white when you pick a leaf off a stem. Showy milkweed can be found in agricultural fields, agricultural canals, and in isolated spots in mountain canyons.

Because Monarch females prefer to roost in trees during the late morning and afternoons of hot summer days, when they do fly, they tend to prefer to lay their eggs on milkweeds growing near or under the trees where they roost. More.

In the Great Basin and Rocky Mountains, the key to finding monarch caterpillars on showy milkweed in their habitat is to look on younger, healthier milkweeds growing either in A) an agricultural canal B) on milkweeds taking refuge under Russian Olive Trees in a wet meadow agricultural situation or C) on small pockets of showy milkweed growing in canyons. Younger monarch caterpillar feed on the ventral side of the milkweed where their feeding damage is unique as compared to milkweed bugs in that they burrow a hole in the center of the leaf.

Here is an example of a screen cage used to get monarch females to lay eggs. Place fresh cuttings of milkweed leaves in a water bottle and place them inside the cage. Place the cage either next to a sunlit window or outside. Intermittant of filtered sunlight seems to work better than constant, direct sunlight.

Building such a cage can be somewhat labor intensive unless you have someone good with tools around the house. Another alternative to building a cage is to simply take a five gallon bucket and cut out a 6" by 6" window from the side and replace with nylon netting. Do the same with the lid.

Newly hatched monarch caterpillars--termed first instars--can be cannibalistic if they find another monarch egg. (They might eat it.) The best thing to do is to cut away the monarch egg and place it individually into a small plastic container, and wait for it to hatch.

This is a series of photos of the developing egg of the monarch butterfly as it hatches into a young first instar caterpillar. Photos were taken by William Zittrich. William's website is http://www.wyllz.com/id177.htm.

Here is a photograph of a recently hatched monarch first instar caterpillar.

It is important, while looking for caterpillars in the wild, to familiarize yourself with this particular chew pattern (some call it skeletonizing) that is unique to young monarch caterpillars. Many insects chew on milkweed plants; but if you are familar with monarch's distinctive chewmarks, it will make your caterpillar hunting more productive.

Using this technique (recognizing the unique chewmarks of your early instar caterpillars) can be very helpful with searching for other species of butterflies as well.

This is a picture of milkweed cuttings in water (milkweed bouquet). The quality of your milkweed cuttings will only stay green and useable for about five days at which time you will need to replace it out again. The best way to move caterpillars from old plant to new plant is to cut around the caterpillar with scissors and place it on top of the new cuttings.

Once you have setup your milkweed bouquet and have placed your caterpillars on it, place that inside a rearing cage or a five gallon bucket with a screen lid.
It is important that your rearing setup has a screen lid in order to provide plenty of ventillation; not because the caterpillars need to breathe; but moreso because caterpillar droppings need to dry. (Otherwise caterpillars can get sick.)